J/AJ/150/154 Photometry and spectroscopy of V501 Mon (Torres+, 2015)
Absolute dimensions of the metallic-line eclipsing binary V501 Monocerotis.
Torres G., Lacy C.H.S., Pavlovski K., Fekel F.C., Muterspaugh M.W.
<Astron. J., 150, 154 (2015)>
=2015AJ....150..154T 2015AJ....150..154T (SIMBAD/NED BibCode)
ADC_Keywords: Binaries, eclipsing ; Radial velocities ; Photometry
Keywords: binaries: eclipsing - stars: evolution -
stars: fundamental parameters - stars: individual: V501 Mon -
techniques: photometric - techniques: spectroscopic
Abstract:
We report extensive high-resolution spectroscopic observations and
V-band differential photometry of the slightly eccentric 7.02day
detached eclipsing binary V501 Mon (A6m+F0), which we use to determine
its absolute dimensions to high precision (0.3% for the masses and
1.8% for the radii, or better). The absolute masses, radii, and
temperatures are MA=1.6455±0.0043M☉,
RA=1.888±0.029R☉, and TeffA=7510±100K for the primary
and MB=1.4588±0.0025M☉, RB=1.592±0.028R☉, and
TeffB=7000±90K for the secondary. Apsidal motion has been
detected, to which General Relativity contributes approximately 70%.
The primary star is found to be a metallic-line A star. A detailed
chemical analysis of the disentangled spectra yields abundances for
more than a dozen elements in each star. Based on the secondary, the
system metallicity is near solar: [Fe/H]=+0.01±0.06. Lithium is
detected in the secondary but not in the primary. A comparison with
current stellar evolution models shows a good match to the measured
properties at an age of about 1.1Gyr.
Description:
Spectroscopic observations of V501 Mon were carried out with three
different instruments. They began at the Harvard-Smithsonian Center
for Astrophysics (CfA) in 2005 November, using the now decommissioned
Digital Speedometer (DS) mounted on the 1.5m Tillinghast reflector at
the Fred L. Whipple Observatory on Mount Hopkins (AZ). Seven spectra
were recorded through 2009 March with an intensified photon-counting
Reticon detector, and cover a narrow span of 45Å centered at
5190Å (MgIb triplet). The resolving power of this instrument was
R∼35000, and the signal-to-noise ratios of the spectra range from 13
to 22 per resolution element of 8.5km/s. Thirty seven additional
spectra were gathered from 2009 November to 2015 February with the
Tillinghast Reflector Echelle Spectrograph (TRES) on the same
telescope. This bench-mounted, fiber-fed instrument provides a
resolving power of R∼44000 in 51 orders over the wavelength span
3900-9100Å. The signal-to-noise ratios of the 37 spectra range from
8 to 56 per resolution element of 6.8km/s. The heliocentric velocities
we obtained from the DS and TRES spectra are listed in Table2.
Between 2011 October and 2015 February we also obtained 57 usable
spectra of V501 Mon with the Tennessee State University 2m Automatic
Spectroscopic Telescope (AST) and a fiber-fed echelle spectrograph at
Fairborn Observatory in southeast Arizona. The detector for these
observations was a Fairchild 486 CCD, with 15µm pixels in a
4096*4096 format. The spectrograms have 48 orders ranging from 3800 to
8260Å. Because of the faintness of V501 Mon (V=12.32), we used a
fiber that produced a spectral resolution of 0.4Å, corresponding to
a resolving power of 15000 at 6000Å. Our spectra have typical
signal-to-noise ratios per resolution element of 40 at 6000Å. We
list the final values in Table3.
An extensive program of CCD photometry was carried out using the NFO
WebScope ear Silver City, New Mexico, for the purpose of gathering an
accurate V-band light curve of V501 Mon for analysis. A total of 6729
images were obtained over 281 nights between 2005 January and
February. Table5 lists these differential photometric measurements.
Measurements of the times of eclipse for V501 Mon collected from the
literature are listed in Table1, and cover approximately seven
decades.
Abundances for individual elements are listed in Table7.
Objects:
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RA (ICRS) DE Designation(s) (Period)
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06 40 41.73 -01 06 40.0 V501 Mon = TYC 4799-1943-1 (P=7.02)
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 36 46 Times of eclipse for V501 Mon
table2.dat 60 44 Heliocentric radial velocity measurements of
V501 Mon from CfA
table3.dat 60 57 Heliocentric radial velocity measurements of
V501 Mon from Fairborn Observatory
table5.dat 19 6860 Differential V-band measurements of V501 Mon
table7.dat 68 17 Abundances from our disentangled TRES spectra
of V501 Mon
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See also:
B/vsx : AAVSO International Variable Star Index VSX (Watson+, 2006-2014)
B/gcvs : General Catalogue of Variable Stars (Samus+ 2007-2013)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/259 : The Tycho-2 Catalogue (Hog+ 2000)
J/AN/334/860 : Catalogue of eclipsing variables. Version 2 (Avvakumova+, 2013)
J/AJ/142/185 : Properties of the eclipsing binary stars HY Vir (Lacy+, 2011)
J/AcA/54/207 : Ephemerids of eclipsing binaries (Kreiner, 2004)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 11 F11.5 d HJD [30077.2/56676.7] Heliocentric Julian Date
(HJD-2400000)
13- 19 F7.5 d e_HJD [0.0002/0.0025]? Error in HJD (listed as
published) (1)
21 I1 --- E [1/2] Eclipse (1=primary, 2=secondary)
23- 25 A3 --- Type Type of observation (pg=photographic
measurement or CCD=more modern determination)
27- 34 F8.5 d O-C [-0.05/0.06] The (O-C) residual (2)
36 I1 --- Ref [1/9] Source of observation (3)
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Note (1): Uncertainties for the photographic measurements are estimated to be
ε=0.025days, as explained in Section 4.
Note (2): O-C residuals are computed from the combined fit described there.
Note (3): Sources for the times of eclipse are:
1 = http://var2.astro.cz/EN/brno/eclipsing_binaries.php
2 = Brat et al. (2007OEJV...74....1B 2007OEJV...74....1B);
3 = Measured from a minimum observed by M. Wolf (2015, private
communication);
4 = Lacy (2006IBVS.5670....1L 2006IBVS.5670....1L);
5 = Zejda et al. (2006IBVS.5741....1Z 2006IBVS.5741....1Z);
6 = Lacy (2009IBVS.5910....1L 2009IBVS.5910....1L);
7 = Lacy (2011IBVS.5972....1L 2011IBVS.5972....1L);
8 = Diethelm (2013IBVS.6063....1D 2013IBVS.6063....1D);
9 = Lacy (2014IBVS.6098....1L 2014IBVS.6098....1L).
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Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 12 F12.4 d HJD Heliocentric Julian Date
14- 19 F6.2 km/s RVA [-90.7/64.5] Primary heliocentric radial velocity
21- 24 F4.2 km/s e_RVA [0.16/1.19] Uncertainty in RVA
26- 30 F5.2 km/s O-CA [-1.24/1.76] Primary (O-C) residual
32- 37 F6.2 km/s RVB [-87.1/90.2] Secondary heliocentric radial
velocity
39- 42 F4.2 km/s e_RVB [0.42/3.1] Uncertainty in RVB
44- 48 F5.2 km/s O-CB [-2.16/3.61] Secondary (O-C) residual
50- 55 F6.4 --- Phase [0/1] Orbital phase
57- 60 A4 --- Inst Instrument used (DS or TRES; only for Table2) (1)
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Note (1): Facilities defined as below:
DS = Digital Speedometer on the 1.5m Tillinghast reflector at
the Fred L. Whipple Observatory on Mount Hopkins (AZ);
TRES = Tillinghast Reflector Echelle Spectrograph on the 1.5m Tillinghast
reflector at the Fred L. Whipple Observatory on Mount Hopkins (AZ).
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
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1- 13 F13.5 d HJD Heliocentric Julian Date
15- 19 F5.3 mag DVmag [2.2/3.1] Differential V band magnitude
(variable minus comparisons)
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Byte-by-byte Description of file: table7.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Z [11/56] Atomic number
4- 8 A5 --- El Element and ionization degree
10- 13 F4.2 [-] Abd1 [2.52/7.83]? Logarithm of the number abundance
for the primary (1)
15- 18 F4.2 [-] e_Abd1 [0.05/0.11]? Error in Abd1
20- 24 F5.2 [Sun] [X/H]1 [-0.63/1.76]? Logarithmic abundance relative
to the Sun for the primary
26- 29 F4.2 [Sun] e_[X/H]1 [0.07/0.14]? Error in [X/H]1
31- 33 I3 --- N1 [3/159]? Number of spectral lines measured for
the primary
35- 38 F4.2 --- Abd2 [2.17/7.52]? Logarithm of the number abundance
for the secondary (1)
40- 43 F4.2 --- e_Abd2 [0.04/0.14]? Error in Abd2
45- 49 F5.2 [Sun] [X/H]2 [-0.08/0.06]? Logarithmic abundance relative
to the Sun for the secondary
51- 54 F4.2 [Sun] e_[X/H]2 [0.06/0.15]? Error in [X/H]2
56- 58 I3 --- N2 [4/126]? Number of spectral lines measured for
the secondary
60- 63 F4.2 [-] loge [2.18/7.6] Reference photospheric solar value
(log ε☉) (2)
65- 68 F4.2 [-] e_loge [0.03/0.09] Error in logE
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Note (1): On the usual scale in which A(H)=12.
Note (2): From Asplund et al. (2009ARA&A..47..481A 2009ARA&A..47..481A).
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 27-Jun-2016